Identification of a UDP-glucose pyrophosphorylase from cotton (Gossypium hirsutum L.) involved in cellulose biosynthesis in Arabidopsis thaliana.

UDP-glucose pyrophosphorylase is an important regulatory enzyme for the development of plants and a critical enzyme in synthesis of glycogen. Here, we reported the cloning of a full-length UGP cDNA from cotton, named GhUGP. Real-time PCR analysis indicated the GhUGP expression in root, stem, leaf and flower of cotton, with a higher level in flower and root. The transcription level of GhUGP depended on sucrose and light in short time and increased under low temperature, but decreased in O(2) deficiency. Interestingly, the expression of GhUGP was significantly up-regulated after ethylene induction in cotton ovules. The over-expression of the GhUGP in Arabidopsis showed discrepant phenotype: increase in height and growth rate when compared with control lines. What is more, the transgenic Arabidopsis had increased contents of soluble sugars, starch and cellulose, but not in lignin content. Collectively, these results indicate that cotton UGPase participates in sucrose/polysaccharides metabolism and cell wall biosynthesis and provide theoretical deduction supporting GhUGP as a good candidate gene for improving the development of cotton fibers cell.